Pictures, photographs & phones

[Puffs]

Recently an issue came up with an ETZ250 being displayed upside-down, in the viewtopic.php?f=19&t=11070 thread, under certain circumstances.

The EXIF header of that pic is attached, see that the orientation of this pic is set to 180°. Some software take the content of that EXIF header that into account, but not all. For instance, on Vista the preview of the ETZ250 pic is upside down, as it is on WXP, and the downloaded full pic too. But on a W10 box, or modern phones, both the preview & the downloaded pic are shown right side up. I haven't tested it on other platforms, but doubtlessly there'll be a spread: it depends on the views of the software designer how his software deals with those meta data (data about data).

Phones & digital cameras contain a light sensitive chip (CCD?), which is fixated into the device. Hence the output depends on the orientation of the device, as do the contents of the digital file. In older cameras, their design automatically caused the user to hold it the proper way, but modern phones can be used in any orientation. This is particularly useful if you want a pic in either portrait or landscape, but it also caters for users who want to hold their device upside-down. To this end, EXIF headers were added to those digital photographs; they contain all sorts of information, see the attached pdf. And often they contain more, for instance on my phone also the explicit GPS coordinates of where the pic was taken are also included (which can be useful for storyboard type applications). And a few more bits & bobs. Anyway, software can then look inside that EXIF header for information about the photo, and treat it accordingly. But if you take a picture with the phone held upside-down, the data of that picture is upside down.

Nowadays, all the pics I post on an open forum are taken with my phone, but I always edit them before posting, for several reasons. Firstly, I do not wish to publish irrelevant or private details as are found in the EXIF header, but more importantly, publishing it at the resolution taken is rarely required, and just fills up the disks of that forum. A photo of a bike doesn't need to take 4MB, I get the picture fine at a mere 284kB, 960x720 (or even half of that, at 640x480, see the attached zip). If you want to show more detail, just post a pic zooming in on that detail. And also, few people browse at 4128x3096, screen resolutions are normally less. And then finally, you do not know what software your public will use to look at your pic, so relying on some meta data, to correct intrinsically wrong data, is bad practise; IMO better post it corrected.